Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Original Research

Volume 28, December 2024, pages 76-87

Antioxidant and anti-inflammatory activities, bioaccessibility, transmembrane transport of major phenolics from selected floral honeys using Caco-2 BBe1 cell model

Figures

Figure 1.
Figure 1. CAA of Caco-2 BBe1 cell treated with 0.1, 0.2, 0.5 and 1.0 g HE/mL of the phenolic extracts of alfalfa, buckwheat, clover, and orange honeys (a), and 1 mM of major phenolic compounds in honeys (b). Value are expressed as CAA Unit (%) and presented as mean ± SD, n = 3. Shared letters indicate no significant difference (p < 0.05).
Figure 2.
Figure 2. Effect of the phenolic extracts of alfalfa, buckwheat, clover, and orange honeys on endogenous antioxidant enzyme activities (a: GR; b:GPx; c: SOD; d: CAT) in H2O2-stimulated Caco-2 BBe1 cells. The negative control (NC) represents untreated cells. Positive control (H2O2) represents cells treated with H2O2 only. Values are presented as mean ± SD, n = 3. Shared letters indicate no significant difference (p < 0.05).
Figure 3.
Figure 3. Released IL-8 of Caco-2 BBe1 cell treated with 2 ng/mL of TNF-α in combination with 0.25, 0.5 and 1.0 g HE/mL of the phenolic extracts of alfalfa, buckwheat, clover, and orange honeys. Value are expressed as IL-8 concentration and presented as mean ± SD, n = 4. Shared letters indicate no significant difference (p < 0.05).
Figure 4.
Figure 4. Apical, basal, and Caco-2 BBe1 cell uptake fractions of major phenolic compounds in the extract from alfalfa (a), buckwheat (b), clover (c), and orange honeys (d) after 6 h incubation. The percentage was determined by the ratio of the concentration of each compartment to the original extract (1.0 g HE/mL). Values are presented as mean ± SD, n = 3. Shared letters indicate no significant difference (p < 0.05).
Figure 5.
Figure 5. MS/MS spectra of PCB (a) and its metabolites (P1, b; P2, c) extracted from basolateral side of Caco-2 BBe1 cells after 6 h incubation.
Figure 6.
Figure 6. HPLC chromatograms of phenolic compounds extracted from basolateral side of Caco-2 BBe1 cells after 6 h incubation with 100 μM PCB, 1 g HE/mL alfalfa, buckwheat, clover, and orange honey extracts.
Figure 7.
Figure 7. HPLC chromatograms of PCB and its metabolites P1 and P2 extracted from basolateral, apical, cells of Caco-2 BBe1 cells after 6 h incubation with 100 μM PCB.

Tables

Table 1. Antioxidant activities of honey extracts and their major phenolic compounds
 
Mean ± SD (n = 3)
Means followed by a common letter within the same column (honey extracts or phenolic compounds) are not significantly different by the Tukey’s HSD test at the 5% level of significance.
Honey extractsFRAP (µmol AAE/g honey)DPPH (µmol TE/g honey)ORAC (µmol TE/g honey)
Alfalfa0.709 ± 0.012d0.365 ± 0.007c1.651 ± 0.052c
Buckwheat1.781 ± 0.018a0.918 ± 0.009a3.377 ± 0.112a
Clover0.809 ± 0.001c0.401 ± 0.028c2.500 ± 0.030b
Orange0.954 ± 0.042b0.583 ± 0.013b1.484 ± 0.122c
Mean ± SD (n = 3)
Means followed by a common letter within the same column (honey extracts or phenolic compounds) are not significantly different by the Tukey’s HSD test at the 5% level of significance.
Phenolic compounds (PCs)FRAP (µmol AAE/µmol PC)DPPH (µmol TE/µmol PC)ORAC (µmol TE/µmol PC)
p-Hydroxybenzoic acid<0.050<0.1257.274 ± 0.232b
Caffeic acid3.382 ± 0.075a1.049 ± 0.039a7.356 ± 0.688b
p-Coumaric acid0.480 ± 0.043d0.269 ± 0.060d5.609 ± 0.192c
Isoferulic acid1.560 ± 0.063c0.395 ± 0.032c6.339 ± 0.363bc
Pinobanksin-5-methyl ether<0.050<0.1254.070 ± 0.117d
Pinobanksin<0.050<0.1253.257 ± 0.493d
Kaempferol2.643 ± 0.027b0.868 ± 0.033b11.303 ± 0.226a
Pinocembrin<0.050<0.1253.549 ± 0.359d

 

Table 2. Bioaccessibility of major phenolic compounds in honeys through in vitro digestion
 
Relative bioaccessibility (%), Mean ± SD, n = 3
AlfalfaBuckwheatCloverOrange
Means followed by a star symbol (*) indicate a significantly difference between before and after in vitro digestion by the Tukey’s HSD test at the 5% level of significance. P5ME, Pinobanksin-5-methyl ether
p-Hydroxybenzoic acid111.3% ± 2.3%*96.7% ± 4.5%106.5% ± 3.9%97.2% ± 1.7%
Caffeic acid79.9% ± 2.3%*86.8% ± 4.0%*89.5% ± 7.9%78.4% ± 1.5%*
p-Coumaric acid93.2% ± 3.7%92.1% ± 4.4%95.5% ± 5.9%91.6% ± 1.2%*
Isoferulic acid103.1% ± 3.1%84.5% ± 17.9%111.8% ± 15.0%89.5% ± 17.7%
P5ME94.8% ± 0.5%*94.4% ± 1.9%*100.2% ± 5.0%89.9% ± 6.0%
Pinobanksin88.0% ± 0.8%*83.3% ± 2.9%*96.4% ± 3.3%78.9% ± 1.4%*
Kaempferol40.5% ± 2.7%*48.5% ± 2.4%*49.6% ± 4.1%*40.9% ± 4.1%*
Pinocembrin87.5% ± 2.4%*84.4% ± 1.1%*95.8% ± 4.6%80.6% ± 0.9%*